Reading "Art of Problem Solving : Vol. 1". Stuck on Excercise 1-6 :
$$ {\sqrt2\over \sqrt6-2} $$
I know, we must rationalize, multiplying by
$$ { \sqrt6+2\over \sqrt6+2} $$
However, what would the final product be? Thanks!
Reading "Art of Problem Solving : Vol. 1". Stuck on Excercise 1-6 :
$$ {\sqrt2\over \sqrt6-2} $$
I know, we must rationalize, multiplying by
$$ { \sqrt6+2\over \sqrt6+2} $$
However, what would the final product be? Thanks!
specifically would be:
$$\frac{\sqrt{2}}{\sqrt{6} - 2} \cdot 1 = \frac{\sqrt{2}}{\sqrt{6} - 2} \cdot \frac{\sqrt{6} + 2}{\sqrt{6} + 2} = \frac{\sqrt{2}\sqrt{6} + 2\sqrt{2}}{6 + 2\sqrt{6} - 2\sqrt{6} - 4}$$
in these last term remember that $(a + b)\cdot(a - b) = a² - ab + ab - b²$ for this reason in the denominator $({\sqrt{6} - 2}) \cdot ({\sqrt{6} + 2}) = \sqrt{6}² - 2\sqrt{6} + 2\sqrt{6} - 4 = 6 - 4 = 2$
So,
$$\frac{\sqrt{2}\sqrt{6} + 2\sqrt{2}}{6 + 2\sqrt{6} - 2\sqrt{6} - 4} = \frac{\sqrt{2\cdot6} + 2\sqrt{2}}{2} = \frac{\sqrt{12}}{2} + \frac{2\sqrt{2}}{2} = \frac{\sqrt{4\cdot3}}{2} + \sqrt{2} = \frac{\sqrt{4}\sqrt{3}}{2} + \sqrt{2} = \sqrt{3} + \sqrt{2}$$